How to Make Fermented Lentils
Lacto-fermented lentils are a quick-fermenting legume that gains probiotic benefits and improved digestibility through fermentation. The tangy lentils work well in salads and grain bowls.
Category: Legumes & Soy · Method: Lactic Acid · Time: 5-10d · Difficulty: 1/5 · Yield: varies · Temp: 18-22°C
History
Lentils are one of humanity's oldest cultivated crops, dating back 8,000 years. Fermented lentil preparations appear in South Asian cuisines, where fermented batters for dosa and idli combine lentils with rice.
Ingredients
- 2 cups (approx. 400g) Lentils — Green or brown, cooked al dente and cooled
- 2-3% of total weight Sea salt — Calculate based on the combined weight of lentils and water (approx. 15-20g)
- As needed Filtered water — Fresh filtered water is preferred over cooking liquid to prevent sliminess
- 1-2 Bay leaf — Adds tannins which help maintain legume structure
Equipment
- Jar
- Fermentation weight
Instructions
Cook and Cool
Cook lentils until just tender (al dente). It is vital to drain and rinse them with cold water to remove excess starch and stop the cooking process, which prevents a mushy ferment.
Time: 25-30 min
Tip: Do not overcook; the lentils will soften further during fermentation.
Brine Preparation
Place the cooked lentils in a jar. Add the bay leaf. Weigh the jar's contents and add enough filtered water to cover the lentils by one inch. Calculate 2.5% of that total weight in salt and stir it in, or pre-mix a 2.5% brine (25g salt per 1 liter of water).
Time: 10 min
Tip: A precise salt ratio is critical for safety in low-acid, high-protein foods.
Submerge and Seal
Place a fermentation weight over the lentils to ensure they remain completely submerged under the brine. This prevents aerobic mold and yeast growth.
Time: 2 min
Tip: If lentils float, use a cabbage leaf as a 'follower' under the weight.
Ferment
Store at 18-22°C for 5-7 days. Check daily for activity. The lentils are ready when the brine is cloudy, they taste pleasantly tart, and the pH has dropped to 4.6 or lower.
Time: 5-7 days
Tip: Use pH strips to verify the acidity for long-term safety.
Fermentation Timeline
- Day 1-2: Start — Slight bubbling begins.
- Day 3-5: Active — Sour smell develops.
- Day 5-7: Ready — Pleasantly tangy.
Signs of Success & Spoilage
Good signs
- Mild sour/tangy taste
- Intact, firm lentils
- Active bubbling in the first 3 days
- Clean, pickle-like smell
- pH level of 4.6 or lower
Warning signs
- Mushy or disintegrating texture
- Putrid or sulfurous odor
- Slimy/viscous brine (ropiness)
- Surface mold or kahm yeast
- pH level above 4.6 after 7 days
Troubleshooting
- Too soft
- Cause: Over-cooked Solution: Cook al dente next time.
Storage
Refrigerated Keeps 2-4 weeks. Keep lentils submerged in their brine even during refrigeration to maintain quality.
Health Benefits
- Protein
- Iron
- Fiber
- Probiotics
- Folate
Serving Suggestions
- Salads
- Grain bowls
- Soup addition
- Tacos
- Curries
Related Legumes & Soy Ferments
Other Lactic Acid Ferments
- Sauerkraut — Vegetable
- Kimchi — Vegetable
- Kefir — Dairy
- Pickles — Vegetable
- Yogurt — Dairy
- Hot Sauce — Condiment
- Water Kefir — Beverage
- Kraut-Chi — Vegetable